EVOLUTIONAL PSYCHOLOGY 73 



ensemble of plants acts as a useful and indispensable com- 

 plement of the ensemble of animals. Once such collective 

 usefulness was soundly established, its very success led to many 

 temptations. It became possible for some species to abandon 

 the road of biological rectitude and for a time to flout the bio- 

 moral principle of co-operation. Yet the mere possibility of such 

 a disastrous course is no justification, as I believe I have shown, 

 for the view that non-reciprocal methods are in any real sense 

 successful or superior methods. 



Considering that the truly integrative, i.e., symbiotic, prin- 

 ciple has so long been overlooked, it cannot cause wonder that 

 a most vital question of Psychogenesis has not even been mooted, 

 namely, as to whether our physiological complement, the plant, 

 acts also in an important manner as our psychological complement. 

 Are we in any sense plant-inspired, just as we are to a large 

 extent plant-fed and plant-" respired ? " Is our thinking to any 

 important degree directly determined by the plant ? There seems 

 no lack of evidence to show that there is a profound connection 

 between brain and food. According to Bechstein,* in Germany, 

 young bull-finches that are to be taught to sing particular tunes, 

 must be taken from the nest when the feathers of the tail begin 

 to grow, and must be fed only on rape seed soaked in water, and 

 mixed with white bread. Instruction is said to succeed best 

 when infused, as it were, with such food. The finches learn 

 those airs most quickly and remember them best which they 

 have been taught immediately after eating their special food 

 (cross-food). 



The honey-bee, a symbiotic cross-feeder par excellence, with 

 a relatively high development of intelligence is a further example 

 of what I mean. It seems to draw in its " wisdom "with the 

 food. There is also the case of the honey-ants. 



These ants (says Mr. P. Leonard in the Scientific American, Supp. 

 gth December, 1916), do not display such a wolfish eagerness to acquire 

 chance scraps of food, as is shown by other species, who live from hand 

 to mouth. Theirs is an inoffensive character. Mr. Leonard goes on to say 

 that whilst among the solitary insects, such as the flies, the moths and 

 beetles, only a very small percentage of their numerous offspring ever 

 reach maturity, owing to parental neglect, " among ants, under favour- 

 able conditions, the infant mortality is practically nil. 



We are further told : The " ants have shown the possibility 



* " Habit and Instinct," Lloyd Morgan, P., 176. 



